1. Field of the Invention
The present invention relates to hot plug devices and methods of controlling power to a hot plug device.
2. Background of the Related Art
Many systems require the ability to hot plug a device into the system, and control the in-rush current seen by the charging of input capacitance. In most technologies there is a balance between charging the capacitance as fast as you can so the FETs are not in a linear mode too long, and not tripping the over current of the regulator or any other upstream power supply. The main issue seen in industry is the fact there is an impedance that is lower than the over current trip point, but high enough to damage a FET if turned on into this impedance. This exposes hot plug mechanisms to cases where, if there is a failure on the rail and the impedance is a soft short, it can lead to severe power dissipation in the turn on FETs, and can lead to a double fault causing a severe burn in a server environment.